Comparisons of a class of IGCC polygeneration/power plants using calcium/chemical looping combinations

To retrofit the traditional integrated gasification combined cycle (IGCC) plants, four plant designs using different combinations of the chemical-looping air separation (CLAS), calcium-looping (CaL), and syngas chemical-looping (SCL) are presented, where the modeling of calcium/chemical looping cycles in fast fluidized-bed and moving-bed reactors have been validated by experimental data. The IGCC polygeneration plants (Designs 1 and 2) and the IGCC power plants (Designs 3 and 4) are developed in an integration simulation platform, and their performances in terms of gross power efficiency (GPE), net thermal efficiency (NTE), carbon emission rate (CER) and water recycling rate (WRR) are evaluated. The comparison results show that (i) Design 1 possesses high thermal efficiency and low water consumption since the SCL cycle can improve NTE and increase WRR by producing the high-purity hydrogen and recovering water from exhaust gases, and (ii) Design 4 possesses high power efficiency and low CO2 emissions since a combination of Rankine and Brayton cycles is integrated to increase GPE and CO2-rich gas is partially recycled in the CLAS cycle to decrease CER. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.